While you wait for answers, we may have found some information which could help you.
Click here for Wall Mounted Boilerwhat boiler would i replace my thorn 44/54 with?
thorn m44 boiler fault?
unable to light pilot on thorn m44/54b boiler?
thorn back boiler housewarmer s?
thermocouple?
Location of pilot light Thorn Housewarmer Super back boiler?